Quick questions on Nuclear fission and fusion: WACE Year 12 Physics Unit 4

In fission a heavy nucleus absorbs a neutron, becomes unstable and splits into two medium-sized daughter nuclei, releasing two or three neutrons and a large amount of energy. A typical example is

In fusion, light nuclei combine to form a heavier nucleus, for example deuterium and tritium fusing to helium:

A routine skill is to complete or check a nuclear equation by conserving both nucleon number (the top number) and proton number (the bottom number) across the arrow. The sum of the top numbers on the left must equal the sum on the right, and likewise for the bottom numbers. This lets you find a missing particle: for example, if the left side has total nucleon number $236$ and the named products account for $233$, the missing neutrons make up the difference of $3$. The same bookkeeping identifies an unknown daughter nucleus by its proton number (which fixes the element) and nucleon number.

In any answer, anchor the energy release to the binding-energy curve: both processes move nuclei toward the iron peak, increasing binding energy per nucleon, so the products have less mass than the reactants and the difference is released as energy. Quote $E=mc^2$ as the conversion.